


Wrasslin'

by GravityPinefalls



Category: Gravity Falls
Genre: F/M, Mutual Masturbation
Language: English
Status: Completed
Published: 2018-12-08
Updated: 2018-12-08
Packaged: 2019-09-14 01:22:09
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 17,150
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16903434
Author URL: https://archiveofourown.org/users/GravityPinefalls/pseuds/GravityPinefalls
Summary: Mabel and Dipper are getting a bit too old to wrestle.





	Wrasslin'

 

 _I wear my own crown_  
_Of sadness and sorrow_  
_And who'd have thought tomorrow_  
_Would be so strange?_  
_\- R.E.M._

 

* * *

 

The Mystery Twins were - Mabel had to admit - getting a bit too old for this sort of roughhousing. Dipper was increasingly annoyed by it, and Mabel had the feeling it would not be wise to do this unless she and Dipper were alone.  What was cute when they were ten was maybe not so cute now that they were fifteen. But she couldn’t help herself. She’d look for any reason to tackle Dipper, to pin him to the floor, just to show she could. She was, after all, five minutes older than him, and a couple inches taller, and every bit as strong as him.  For now, anyway. He was still a skinny kid, but she didn’t know for how long.

Mabel, meanwhile, was _a woman_.  Technically.  The jury was still out on whether or not this whole “being a woman” thing was a net positive, but in the last few months ago she was finally getting more comfortable with her body, identifying it as something normal to her.  And it wasn’t too bad looking in the mirror and seeing a teenager - practically an adult! - looking back.

Poor Dipper.  He was filling out a little bit, and she noticed he was getting sharper facial features, and even a little peach fuzz on his chin.  When coming out of the shower or getting ready for bed - about the only time she saw him without a shirt - he proudly displayed at least a half-dozen chest hairs.  But his voice was cracking all of the place, and someone set her brother’s “Awkward” and “Sweaty” dials up to eleven. Even worse, and for the past two years, she’d been steadily gaining on him in height.  Boys mature later than girls, they said in sex ed. On one hand she felt sorry Dipper looked closer to a 12-year-old than a high school student (although he wasn’t without company in high school), and on the other hand, she thought that was a fair trade for Dipper not having to deal with She Who Must Not Be Named, the dreaded creature _Feminine Hygiene_.  Still, it genuinely hurt to hang out with people who didn’t know they were twins, and on looks alone, assumed she was Dipper’s big sister.  The few minutes between their births widened out into as much as two years in the eyes of the casual observer, and she could hardly bear the embarrassment on Dipper’s face as she gently corrected the assumption.

So, just as Mabel was getting over her awkward phase, Dipper was in the depths of his own, and she figured a part of that was his disinterest in their goofy wrestling games.  She understood, of course, but that didn’t stop her from complaining when his response to her challenge was to sit still, fake an effort to get free for ten seconds at most, and surrender.

She was very happy that, this time, Dipper seemed willing to play along.  He had been lying on his stomach on the fluffy carpet in the downstairs rec room, chin propped on his elbows, some boring book on occult math in front of him.  Boring enough, in fact, that when Mabel pounced - accentuating this by actually announcing “Mabel pounce!” as is tradition - and straddled Dipper’s lower back, he did not sigh and tap his palm on the floor and announce her flawless victory.  Instead, to Mabel’s delight, he spun around beneath her, grabbed her shoulders, and pushed her to the floor.

With Mabel knocked aside, wracked by gigglefits, Dipper had no trouble grabbing her arms and pin them to the ground, kneeling above her.  Her legs were free though, and she lifted her hips, wrapping her legs around Dipper’s chest. She had almost, but not quite, enough leverage to throw him off balance, and in wiggling back and forth her legs slid downward to his waist.  She locked her ankles behind his lower back, fixing him in place, arching her back just enough to put her weight on him and keep him still.

“So what’s this?” she said.  “The return of Professor Ghosthunter?  Trying to reclaim the world championship from the undefeated Masked Bag of Kittens, Each of Which Are Also Wearing Masks?”

“Mabel, you are like, the _worst_ at coming up with pro wrestling names.”

“Quiet!” she said.  “You’ll give away my secret identity!”

She jerked her arms, trying to free her wrists from Dipper’s - ah, _Professor Ghosthunter’s_ hands, but he held fast, and her movements only served to-

“Ouch,” she said.  “Hair.”

“Sorry!”

He moved her hands further to the sides, away from the river of auburn hair splayed over the rug.  Once clear he was repositioned - she wasn’t a cheater! - she tried another move, attempting to pull Dipper closer with her legs.  This didn’t work either, although tightening and loosening her grip with her legs, and smacking Dipper’s pelvis with her butt, seemed to really really annoy him.  So of course that’s exactly what she did.

Dipper’s face started to blush, which encouraged her even further.

“C-come on,” he said, twisting a bit to get loose.  “That feels really weird.”

She laughed.  Perfect. She was going to win this one.  With her butt.

Ah, wait.  He wasn’t giving up just yet.  Dipper began scooting backward, dragging her back along the thick rug, as if that might loosen the death-grip of her legs.   Her loose sweater rode up her back, and she began to understand his strategy. _Rugburn!  That notorious Professor Ghosthunter, using the ring itself against me!  What’s next - hitting me with props? Look out for folding chairs, Mabel!_

Dipper paused a moment, looking at her side-eyed, and loosened his grip on her wrists.

“Ah, time out, Mabel  … you might want to fix that …”

Glancing downward, she noted he had scooted her along enough of the rug to ride her red sweater and white-and-pink-striped undershirt most of the way up her chest.  Stupid. If she had just a little bit of patience she would have changed into a t-shirt before this. _It’s probably stretched out already.  Rookie mistake, Mabel._

“Yeah, just a sec,” she said, and yanked the sweater and undershirt up off her head, tossing the tangle of fabric safely aside.

Dipper’s expression was … unexpected.  Like, blushing and turning white at the same time.  Is that even possible? _Oh my god, my bra came off, didn’t it?_

She glanced down, but to her relief, her green sports bra was still in place.  Nothing indecent - heck, she’s been to track practices before wearing this exact sports bra as a top.  And on top of that, this was _Dipper_ .  They’ve shared a bedroom most of their lives.  I mean, yeah, the last time they changed clothes in front of each other they were probably nine or ten, back before puberty chewed them up and spat them out.  (Dipper was technically still being thoroughly masticated by aforementioned puberty.) _(Hee hee, masticate.)_  But Mabel had no doubt in her mind that, in the sort of code-red wardrobe malfunction she had so briefly envisioned - a (gasp!) _full-double-boob-out_ \- she would not freak out.  After all, Dipper was the one person in the world who wouldn’t laugh at her or take advantage of her, the one person who would help her cover up and make her feel perfectly at ease, the one person who would, without fail, turn the situation around and have her laughing.

All the more confusing then, that Dipper looked shocked and scared and uncomfortable, even though he hadn’t even _seen_ anything.

This required some investigation, she knew, but for the moment, Dipper was flustered, for whatever reason, and the dummy should know better than to show such a weakness in the middle of a match.

“Time in!” she said, sending Dipper stuttering, hands up in protest, but she’d already unhooked her ankles, grabbed him under the shoulders, and forced him up and backward.  He spat a gasp-groan as his back hit the rug, and now she was atop him, straddling him, legs pinned between her thighs, hands pinned above his head.

“Seriously?” he said.  He shifted back and forth, the fabric of his khaki shorts rubbing against her green-and-black-striped yoga pants.

“I’ve got you now!” she said.  Wiggling her butt in a pre-victory dance, hands above her head.

Dipper grabbed her hips, his voice panicked.

“Stop! Mabel, stop moving like that!”

“Fool!” she said.  “Once Masked Bag of Kittens begins her victory dance, no man on earth can stop her!”

She closed her eyes, waving her hands above her head, shifting her hips back and forth to an imaginary dance track, humming to herself.  Dipper had obviously given up; she’d be done teasing him in a few seconds.

“N-no,” Dipper gasped.  “Mabel, you have to-”

Something _happened_.  The hands at her hips gripped tightly.  Mabel opened her eyes to see Dipper’s face screwed up in agony, the muscles in his neck tense.  She froze, her heart plummeting in her chest as she watched Dipper choke out an anguished sob.

“Oh, no, oh geez, I’m sorry Dipper - I didn’t mean to hurt you!”

She lifted her weight off him - maybe the carpet wasn’t as soft as she thought, or maybe she weighed more than she realized, but obviously she’d injured his pelvis or tailbone or something like that - and got on all fours, placing her forehead to his, looking into his watery eyes.

“I’ll - I’ll fix it, Dipper.  Just tell me what to do.”

He was shaking beneath her, gasping for breath, and moved his hands up from her hips to her back, and pulled her down atop him.  With her cheek to his cheek, she lay there, letting the shock of his injury dissipate as he crushed her to his chest. For several moments his hips twitched beneath her, and then became still, and soon Dipper’s breathing became normal.  She pulled back, sitting beside him, looking him over.

“I mean it, I’m really really sorry.  How bad is it? Should I get some ice, or-”

She froze.  

 _Oh, it’s bad, Mabel.  It’s really really really bad._  

Appearances notwithstanding, Dipper was Technically an Adult.   _I present to you Exhibits A through Z._  Oh, god, she had mentally prepared herself for this - something _like_ this, where she’d accidentally walk into Dipper having some Dipper Time and she’d be super-cool about it and not make him feel bad or ashamed and just be all “lock the door next time, doofus” and that would be it.  Maybe Dipper had the exact same thoughts, and would be totally cool if he likewise stumbled into a session of Mabel Time. I mean, law of probabilities and all, you can’t have two hormonal teenagers in the same house and expect them to never make mistakes.  

And, ugh, it would’ve been bad enough if he’d … _you know_ … in his _pants_ , and from the wet spot on the front of his shorts it looks like that took the brunt of it.  But her wrestling moves must’ve pushed his shorts and underwear down just enough. And, yep, that’s that right there.  The barest hint of Dipper-dick pointing out the waistband of his shorts. Dollops of white liquid on the bottom of his t-shirt and few exposed inches of his stomach.  Which must also mean …

She slipped her hands between her thighs.  Yep. Her yoga pants weren’t sticky earlier, so by process of elimination, the wet spot on her inner left thigh is … _oh boy_ .  That’s what sperm is.  That’s what it feels like.  And it’s … geez, it’s only a few inches away from her … oh god, could she get _pregnant_ from this?  How far can those little buggers swim?

“Dipper,” she gasped.  “Oh god, Dipper, I’m so sorry-”

He waved her off, stumbled to the bathroom on unsteady legs, and when she attempted to grab at his arm or shoulder to help him walk, he brushed her aside without a word.

She quickly looked around.   _Hide the evidence_.  Nothing on the rug.  Looks like their clothes took all the damage.  She threw on her shirt and wrapped her sweater around her waist to hide the stain.  Waited a moment. Their parents were on the other side of the house, hard to hear from the basement and vice versa, but she took no chances.  No sounds of approach. She ran to the half-bath, tapped on the door.

_Freaking out happens later.  Until then, Mabel, get your shit together._

“Dipper, you can hate me all you want after this, but right now, I need you to sit still until I get back, all right?  If Mom or Dad come downstairs, act like you have a stomach ache.”

No response, but she had the strong feeling Dipper nodded at her through the closed door.

Mabel grabbed an air freshener out of the laundry room closet, spritzed around the rec room, and then ran upstairs.  Friendly wave to Mom and Dad. Mom noticing the sweater around her waist and nodding imperceptibly in mutual understanding.   _Girl issues._  Mabel grabbed a new outfit out of her room, ran to the upstairs bathroom, and stripped down.  Warm washcloth on her thighs, each stroke downward, away from her ladybits. Not enough time for a shower.  New underwear, new pants, new sweater. Back to the bedroom. New pair of shorts for Dipper - thankfully, he had at least four pairs identical to the ones he had been wearing.  Dipper’s underwear drawer was, like hers, the equivalent of a foreign embassy - under inviolate diplomatic protection - and as such, she simply closed her eyes, stuck in her hand, and grabbed the first underwear-like thing she felt.

Home stretch.  She stuffed Dipper’s clothes under her new sweater and ran downstairs with her soiled clothes in her arms.  Passed her parents again.

“Mabel,” her dad said.  “Did you just change-”

“ _Dear_ ,” her mom said, which was the end of _that_ line of inquiry.  And, of course, perfect cover for Mabel doing a small load of laundry in the middle of the day while being left completely alone.

Returning to the downstairs bath, she knocked on the door.

“Okay, I got you something new to wear.  I’m gonna run everything through the wash but you gotta give me your stuff right now.”

“Mabel, you can’t … you don’t want to touch that gross stuff…”

“Yeah, well.  Barn door. Horses.  Trust me, I have an out for us.  So come on, give ‘em up.”

The lock clicked open.  As it was only a half-bath, Dipper had nothing bigger than a hand towel to retain his modesty, but she paid no attention, tossed him his change of clothes, grabbed the damp shorts and underwear in the sink, and brought them and her clothes to the laundry room.  A thorough rinse in the laundry sink, a spin in the washer, a spin in the dryer, and all evidence of the crime would be erased.

Mabel slammed the washer closed, and with the urgency of repairing the problem passed, could no longer hold back her despair.

_“Evidence of the crime.”  That’s what that was, isn’t it?  I was playing with Dipper, and he accidentally got aroused, and immediately told me to stop.  Begged me to stop. And I didn’t. I didn’t know what was happening, but I knew he was telling me to stop and I didn’t stop.  I made him have an orgasm. I made him show me something he’d never, ever want to show me._

_My own brother.  Begging me to stop.  Because it didn’t feel good.  He didn’t want it. But he couldn’t control his body.  And he came, because of me. I took that from him. I took away his control.  What do they call that, Mabel? What do they call it when someone does that to someone else?_

_I’ll give you a hint.  It starts with “r,” rhymes with “grape,” and ends with prison._

Her back against the rumbling washing machine, she slid to the floor, buried her head in her hands, choked back tears, choked back vomit.

_I’m horrible.  I am so horrible.  Everything’s changed now.  Dipper will never trust me again.  Why should he?_

Ten, fifteen, twenty minutes passed.  She had composed herself in time to start the dryer cycle, but she felt horribly empty.  She left the laundry room. Finding the downstairs bathroom door open, she poked her head inside to find Dipper missing.  She returned to the laundry room, waited until the dryer was done, folded the clothes, and put on a cheerful face before going upstairs.  If it was obvious she had been crying, her parents made no mention.

Dipper was in their bedroom, curled up in his bed, facing the wall.  She put his laundry on his dresser and then lay on her own bed. Waiting.  Waiting for him to speak. To forgive her. No, that’s not it. She didn’t want forgiveness.  Didn’t deserve it. She wanted Dipper to hate her. To tell her how angry he was at her. She didn’t want him to be okay with this.  She didn’t want him to act as if her behavior was acceptable.

And the worst possible thing Dipper could have said - the thing that would absolutely break her heart - was exactly what he said to her, before she curled up into her sweater and sobbed quietly.

“I’m sorry, Mabel,” he said, not even looking at her, staring at the wall.  “That was the worst thing I’ve ever done. But I’ll never let something like that happen again.  And to make sure of it, I’ll stay away from you. I promise, Mabel, I won’t touch you ever again.”

* * *

  

“Hey Dipper, can we talk?”

They were in the rec room, watching a movie.  Normally she would have her head on his lap, or be leaning against him, or at very least, splayed out with her foot against his thigh.   _Some_ contact, no matter how little.  She could barely sit still through a movie without it.  But they were on the opposite sides of the couch, a good three feet gap between them, and it was _killing her_.

It had been weeks since _the incident_ and, following Dipper’s lead, she had spent all this time pretending it had never even happened. They shared the same bedroom, followed the same routines.  Nothing suspicious, nothing strange. But Mabel felt sick. She lost count of how many left-hanging high-fives, how many un-bumped fists, how many declined awkward-sibling-hugs, she had gone through in the first few days.  And when she stopped trying, and just ignored opportunities for such contact, _that_ felt even _worse_.  She had never noticed before how much she enjoyed even the most casual physical touch from Dipper.  How much she relied on it. Even during their lengthiest fights, they wouldn’t go more than a day without at least a half-hearted high-five.

But the worst part of it - the absolute worst part of it - was that Dipper truly believed _he_ was the bad guy here, that _he_ hurt Mabel and not the other way around.  How could they possibly rebuild their relationship with such a fundamental rift?  

So she’d been playing this over in her head for days.  She needed to have it out with him, in a situation where they could scream and cry and fight and slam doors, go to bed angry, and start all over again.  It was Friday night, and they had come home to an empty house after school, as their parents had left for a spa weekend that afternoon and would be gone until Sunday.  This was the best opportunity they’d have for a while.

“Uh, sure, Mabel.  What about?”

“I want us to have a Twinmoo.”

“A … a twinmoo?  What the heck is that?”

“You know, like in Lord of the Rings.  An Entmoo, but with twins.”

“Entmoo _t_ ,” Dipper said.

“Oh, but we don’t have time for a Twinmoot,” she said.  “That takes weeks. This is just a Twinmoo. It’s shorter.  More efficient.”

She got a laugh out of him.   _Thank god_.

“All right,” he said.  “So you want to talk about something really serious, then.”

She nodded.

“It’s not about … that _thing_ that happened, is it?”

“Of course it is, Dipper.  Things have been really weird since then!  I can’t take it anymore!”

“Mabel, I’m sorry.  I’ll apologize a hundred times more if you want, but I don’t know what else I can do.”

“Dipper, you have to stop apologizing and _listen_!”

“Mabel…”

“Dipper, please! I need you to stop listening to _yourself_ and start listening to _me_.”

“Mabel … all right.  Got it.”

“We have a day and a half to figure this out,” Mabel said.  “All alone, no interruptions. I think that’s enough time, but … I’m not sure.”

Dipper turned off the TV and tossed the remote aside.

“Well, I’m all yours, Mabel.  Hit me with everything you have.  I know I deserve it and worse.”

She shook her head.

“Just … just _listen_ , Dipper.  First off, all this … what happened wasn’t your fault.   _I_ did it.  I did that to you.  And I can’t take it back.  I don’t know how to make it better.  But I _want_ to make it better.  And I understand if you hate me, and don’t trust me, and that’s why you won’t go anywhere near me anymore.  I just … I just want to know what I can do to make you feel you don’t have to do that anymore.”

“Mabel, come on.  That was all me. It was my fault I let it get that far.  You had no idea what was going to happen. And the worst part  … I mean, it would be bad enough if I just … you know, _finished_ like that.  With you right there, looking at me.  It’s a thousand times worse that it got all over the place.  But even that, I think, I could get over, with enough time. But the worst part … the worst part …”

He sucked in a breath, tears in his eyes.

“Dipper,” she whispered.

“The worst part is that it felt _good_ \- it felt _really really good_ , like nothing I’ve ever felt before.  And it wasn’t just the physical part. Right then, I had thoughts about you that I should never have had.  And when you got off me - when I should have gotten away - I … I didn’t. I just grabbed you and held you close.  I didn’t even _think_ about it.  I just needed to hold you until … until it was finished.”

“Dipper, I know … I mean, I _get it_.  After I put you in that position, I don’t blame you at all for grabbing me like that.  If holding me close made it feel better, then I’m glad that’s exactly what you did.”

“C’mon, Mabel, you don’t mean that.”

“ _Dipper_ ,” she hissed.  

“Right,” he said.  “Sorry. If you really mean it then … thanks.  It really … it really did make it feel a lot better.”

She smiled.

“So at least I did _something_ right,” she said.  “But what did I do wrong?”

“Mabel?”

“I mean, I’m not _stupid_.  If I felt you get hard I’d back off and, you know, let you deal with it,” she said.  “You’re a guy; there’s nothing weird about it. But I didn’t notice anything, so I thought it was fine to move around a bit.  I didn’t even think that you might, you know...”

“Yeah,” he said.  “I’m not sure I even … I mean, I went from zero to a hundred in like a second.”

“Just from me moving around?”

“You taking off the sweater didn’t help either.”

“I _thought_ that got you a little flustered  But I don’t get it. It’s not like I was flashing you.  You’ve totally seen me wearing that sports bra as a top before.  Why was it such a big deal then?”

Dipper shrugged.

“Oh, that’s not an answer.  Come on.”

“Look, I’m being as honest with you as I can, Mabel.  If this is the punishment you’ve chosen for me, then all right, I’ll tell you every humiliating thing I can think of.  I’m sure you already have enough blackmail material to last a lifetime. But you’re _killing_ me here, Mabel.  I won’t be able to take a whole weekend of you rubbing my nose it what I did.  Just call me a sick pervert and be done with it.”

“Dipper,” she said.  “Oh, god, Dipper, it’s not like that at all.  Ah, jeez, I’ve just been asking you all these awful things and you’ve just been spilling your guts and … oh man, it must feel like Truth or Dare but it’s always Truth and it’s always your turn … oh Dipper, I’m so sorry, I didn’t mean to do this to you at all …”

She scooted close, perched on the faux-leather ottoman beside Dipper’s seat on the couch, hands on her knees.

“Truth or Dare,” she said.  “My turn. Ten times over. No limits.”

“Mabel - ”

“ _No limits_.  The most embarrassing, humiliating things you can think of.  Just keep them coming until we’re even.”

“Mabel,” he said, shaking his head.  “I don’t - I don’t want that at all.”

She choked back a sob.  No, of course not. _Of course_ he wouldn’t want that.  She was asking Dipper to _hurt her_ .  And he _couldn’t_.  He wouldn’t want to.  It wouldn’t make him happy.  Wouldn’t even the score.

Of course.  It was obvious, really.  She was ready to take the bullet, but she kept putting the gun in Dipper’s hands.  But that would just mean it was Dipper who pulled the trigger. Dipper who got to bear the blame.  She could even the score, still. She could give Dipper her most embarrassing secrets, to balance out the ones he’d already shared with her.  But she had to volunteer.

She tightened her grip on her knees, took in a breath, and breathed out.

“It was right after we left Gravity Falls that first summer,” she said.  “That October, right after school started, when we were thirteen. That’s when I had my first period.”

“Mabel!” he gasped.

“And it was awful and confusing and it came and went almost totally random all the way into January.  I just started using tampons a few months ago and I’m still getting used to them. I’m crazy paranoid that people know when it’s happening.  I try to act normal, even when my stomach hurts and I’m right at the edge of crying my eyes out or killing every freaking person in the room.  Sometimes both at the same time.”

“Mabel,” Dipper said.  Her face burned, and Dipper was clearly shocked at her speaking so candidly about something so taboo, but the shock on his face was so much better than the pain and sadness moments earlier.  “You don’t … you don’t have to tell me all that stuff …”

“I know.  But I want to, Dipper.  I already embarrassed you so much.  And if I … if I’m gonna know such personal things about you … than it’s only fair … it’s only fair you know the same stuff about me… the grossest stuff I can think of.”

“Mabel, it’s not … it’s not gross.  If you think me knowing about you having periods is gonna freak me out … well, it _doesn’t_.  That’s like, totally normal girl stuff.  There’s nothing weird about it at all.”

“Yeah, you say that, but come on, Dipper.  We’ve been on shopping trips together, and I know how you get when you’re walking down _that aisle_ of the store.  Like you’re walking through a minefield.  And that’s fine. You’re a guy, after all, of course it’s weird for you.”

“If I had to …”  

“Dipper?”

He shook his head.

“If I had to … I mean, if it was an emergency or something … I’d get over it.  You know that, right? After all, it’s just … it’s just a medical thing, that’s all.  If we’re hanging out, and there’s some sort of disaster where you need me to buy something for you, or help you cover up, or anything like that … you know I’ll be there for you, right?”

“I … Dipper …. y-yeah … I guess I know that …”

She felt a blush on her cheeks.   _Of course_ she knew that.  God forbid, they were hanging out, and her Special Time (tee-em) decided to catch an earlier flight and show up on her doorstep ahead of schedule … I mean, yeah, that would be embarrassing as hell, but when push came to shove … I mean, it’s Dipper, so obviously he’s going to have her back, no matter what.

Still, she found this a bit annoying.  She really thought Dipper would freak out more easily than this.   _Fine.  Let’s kick it up a notch._

She steeled herself, leveled her eyes at Dipper.

“All right, then how about this?  I _love_ collecting vagina names.  I hate the c-word, but I think ‘pussy’ is fun even if lots of girls don’t like saying it.”

She was relieved that Dipper gave her a quizzical look at this. _Oh?_ He was curious about this.  Even intrigued. Obvious, really - as bona  fide Teenage Girl, she had all sorts of esoteric knowledge.  Incredibly valuable to a Teenage Boy. Like, Death Star blueprints-level info.   _Many Bothans died for this information._

She grinned.

_Strap in, Dipstick, you’re getting the realio dealio._

“The gross words that still make me laugh are clam, hair-pie, and tuna-town.  Super gross though - don’t _ever_ let me hear you say stuff like that.  Some girls - I don’t know how many, but some - have a secret name for their own.  I call mine Agnes. Oh, and masturbation. This is like super-secret info, but girls totally masturbate just as much as boys.  Maybe more. And we don’t even know we’re doing it when we’re really young. Just that, well, it kinda feels nice in the Agnes to hump pillows and stuffed animals and things.  And it’s this crazy epiphany when you realize what’s really going on, what you’ve been doing in secret. But then puberty knocks you on your butt, Agnes gets all hairy and temperamental and fully operational, and suddenly you’re Touching Yourself with a capital T.”

The words spilled out before she even realized she was speaking them.  Puberty had created a wall between them, not a very big one, not at all, but there were customs agents at that wall, dutifully checking all the things she wanted to share with Dipper, and confiscating anything relating to those sorts of feelings and bodily functions that had started to appear when she was eleven years old or so.  And once she decided to bowl right through, and share everything with Dipper, she found it very hard to stop.

_Oh, holy hell, shoulda backed up a bit there, bit too much info Mabel._

Dipper was transfixed.  “No way. You’re telling me - you actually do that stuff?  I had no idea...”

“Well, I’m way more careful about it than you are, for one.  And, you know, not so much cleanup afterward.”

“O-oh … you mean you knew I  … ah, took care of things? I thought I was really subtle about it.”

“Well, you’re not,” said Mabel.

“Ah…”

“It’s all right, Dipper.  I learned to ignore it. I was never sure if you heard me or not though - most of the time we’re in bed, and I think you’re asleep, but I never really knew for sure…”

He fidgeted in his seat.  Mabel smiled. This was good.  Cards on the table. Revealing everything.  A running contest to find which of them had the best and most embarrassing secret to share.  Her stomach flipped and flopped. She told him about Mabel Time. She told him about _Agnes_ , for pete’s sake.  That sort of embarrassment was something not even Sweater Town could protect her from.  But she wasn’t curled up in fear and shame. She was invigorated. Excited. What seemed like common-sense iron-clad rules were broken, and it felt _great_.

“Mabel,” he said.  “All right, I can’t say you haven’t earned it, so … when the thing happened, between us … do you still want to know what I was thinking, that let it all get away from me so quick?”

She leaned forward, grinning.  This wasn’t the response she expected - she just laid it all out for him, so he didn’t have to be embarrassed anymore.  She was okay with them considering the issue settled. But the look on Dipper’s face was probably the same as she had just minutes ago - the thrill of telling each other the most forbidden things imagingable.

“Lay it on me,” she said.

“It’s screwed up, I warn you,” Dipper said.  “A guy’s sex fantasies … I mean, it’s a psychological _quagmire_.  So don’t read too much into it.  Just because I had a fleeting thought in a moment of extreme circumstances … that doesn’t really mean … you know…”

“Ooo,” Mabel said.  “This is gonna be good.  Spill.”

“All right,” Dipper said.  Drawing in a breath, and then:

“It really felt weird, you banging at me with your hips.  But I had everything under control until you pulled your sweater off.  And yeah, you were wearing that bra, and yeah, it’s near enough to a top.  But for a split second, I thought, _Oh my god, it’s really gonna happen, I’m really gonna see Mabel’s breasts._  And when you tossed your sweater aside, and still had that top on, I was  … I was actually _disappointed_ .  Can you imagine?  And my brain just went with it.  I was actually _fantasizing_ about you taking that top off.  And I don’t know if it’s because it was you, or just because that’s the closest I’ve ever been to a girl doing that to me, or what …”

Mabel’s face burned.  Of course. She wasn’t a little girl anymore.  Yanking her sweater off like that, even if she kept her bra on - that’s something that gets a guy’s attention.  That’s a PG-13 movie thing. Heck, maybe even R-rated if it happens too many times, or they made it so you can see the lady’s nipples through the fabric.

“And just as I was getting my bearings from that,” Dipper continued, “you knocked me over and started moving around and it was like … like …”

“Like we were having sex,” Mabel said.  The flush on her cheeks moved to her neck.  What did it look like from his perspective? Straddling Dipper, wearing a bra, arms up in the air, her weight on him, grinding against Dipper’s - _oh my god, what was I thinking, that wasn’t wrestling at all, that was dry humping, and I was into it, I was totally into it, like I was a little girl humping a pillow and not knowing why it felt good, but I’m not a little girl anymore, I know why it felt good, it felt good because I was rubbing my Mabel Business all over his Dipper Business, and if I hadn’t made Dipper cum … if Dipper let me keep going … I wouldn’t have stopped.  I would have kept going until it was too late for me, and then … and then … oh, God, Dipper…”_

“Y-yeah,” Dipper said.  “Kind of like that. I mean, I could feel your, you know.  Area. And I just totally lost it.”

“S-so it’s just,” Mabel said, “It’s just … just because you’re a guy, and horny as all-get-out … so of course you wouldn’t even think … I mean, I’m your sister, first off, and maybe I look all right, but it’s not like you’d ever think I was pretty or anything …”

“You quit that.  Mabel, you are the most beautiful girl in the world.”

“Oh, come on, be serious, Dipper.”

“I’m serious, Mabel.  For the life of me, I don’t understand how you’re not awash in boyfriends; a girl like you should have them lined up around the block.  I mean, I’m glad you’re not, of course.”

“W-why not?”

He blushed.

“I … I’m not one to screw around with your love life.  I’d never go to a guy who wanted to date you and tell him he’s not good enough for you.  But boy, Mabel, I sure do _think_ it.”

“You really think that?  I never thought you’d be jealous, Dipper.”

“I’m not.  Well, I am, a little, but I can deal with it.  I just … I know you so well. I see how perfect you are.  I want you to find someone who can see that in you. Someone who would absolutely worship you.  And I won’t say a word about it, of course, but if you end up marrying some guy who isn’t absolutely perfect for you … yeah, they’ll be a part of me unhappy about it.”

“Dipper,” she whispered.  She was sweating. It was too hot in this room.  She didn’t even think about it as she pulled her sweater off and tossed it to the couch.  She kept her t-shirt on this time, of course - her bra being insufficiently conservative to serve as a top - but nonetheless Dipper averted his eyes, raised his hand to block his view.

“Mabel, you don’t have to-”

“Don’t have to what?”

He uncovered his eyes.

“O-oh,” he said.  “Never mind…”

That look in his eyes.  Flustered like before. _Holy crap!_

_It can’t be.  There’s no way.  Dipper … does Dipper really want me to keep going?  He said himself it was a fantasy. That it didn’t mean anything.  And still … oh, god, the way he’s looking at me right now … I shouldn’t … I really shouldn’t …_

“Dipper,” she said.  “Do you … do you want me to take my shirt off?”

His face beet red, turning away from her.

“Ah, god, Mabel, nevermind me, I don’t know where my head is at.”

“C’mon, just tell me.  I promise I won’t be mad.”

“Look, Mabel, I know it’s wrong.  And I’m pretty sure it’s something that will go away pretty soon.  But right now, even my _urges_ have urges.  And I’m not staying away from you, and keeping my hands off of you, because I dislike you.  It’s because that’s the only way I can be sure I won’t make an awful mistake. You’ll be my sister for the rest of your life, Mabel.  I don’t want to do something that might screw that all up. So just … just give me a little while here.”

“What … what kind of urges?”

“Mabel, please don’t ask…”

“I-I want to know.  Please, Dipper. They can’t be that bad.”

“They’re _bad_.”

“ _Dipper_.”

He sighed.

“All right, but you might want to do some arm stretches.  You’re gonna need your slapping hand warmed up.”

“I promise I won’t be mad, Dipper.  Come on!”

“Fine.  You really want to know, Mabel?  I’m sitting here, just barely holding myself together. And part of me is really hoping you’ll just drop this, let me get back to this movie, and we can spend a perfectly normal weekend together.”

“And the other part?”

“The other part of me wants to know what might happen if I tell you I want to see you without your shirt on.”

“Is … is that all?” she said.  “Geez, Dipper, I thought you were gonna say something way crazier than that.”

She pulled her undershirt over her head, tossing it beside her sweater.  All right, so this was not one of those acceptable-as-a-top bras, it was a bona fide _undergarment_ , but she didn’t find anything particularly uncomfortable or sexual about showing it off to Dipper.  Heck, she was kind of proud of this one, one of her nicer ones, white with patterns of pale blue clouds trailing rainbows.  I mean, a cool pattern alone ought to upgrade it to almost a bathing suit.

There was nothing sexy at all about this, really, and she knew Dipper would see that too.  They’ve seen each other in their undies before, and not felt anything weird. After all, people standing around wearing only underwear were inherently funny.  That’s just a comedy _fact_.  So of course she couldn’t help giggling to herself, knowing Dipper would surely recognize how silly all this was, and laugh along with her.

Her rainbow-patterned socks made it easy to skate back and forth on the hardwood floor, her waist-length hair flailing about.  A quick slide to one side and then the other - damn, if only the layout of the basement allowed it, she’d be all over a Risky Business impression.

She turned to him, looking down her chest, frowning at her lack of cleavage, and then squeezing her shoulders together in a valiant attempt to produce some.

“Not much to look at, anyway,” she said, her hands cupping her breasts through the bra.  “I mean, a solid B-cup, maybe a C on a good day. And they didn’t come in at the same time, no sir.  Lefty thought she was in a race or something, and it freaked me the heck out, but Righty caught up recently and it looks like they’re neck and neck.  I wish they were bigger but every girl I know with bigger boobs wishes they were smaller, so what do I know, huh?”

Dipper didn’t say anything, prompting her to look up, and see the expression on his face and-

_Oh. Oh hell, what did I do?_

All right, she was not coming across as “goofy,” she could see that now.  The pained look in Dipper’s face stabbed at her heart. She wasn’t making him laugh; her spontaneity and free spirited shirtlessness was failing quite hard at that.  No, she was making him dig his fingers into the couch. She was making his face twist up in some incomprehensible mix of sadness and rage and agony.

 _Mrs. Robinson, are you trying to seduce me?_  

“Dipper, I-”

“ENOUGH!”

Her knees weakened.  She nearly fell on the floor.  He … he _yelled_ at her.  She thought she might throw up.  This … this is what it sounds like … the thing she’d never heard before … Dipper so angry at her he would actually speak to her with such violent intensity.  Such _hate_.

“I _get it_ , all right?  You made your point, Mabel!  So just stop it! It’s done! _We’re_ done!”

He stood, walked past her, went upstairs.  She was too shocked to stop him, to speak to him.

_What did Dipper ‘get’?_

_What was the point I was making?_

_What does he mean ‘it’s done’?_

_What does he mean ‘we’re done’?_

_Oh god._

_Oh god no._

_No no no no no._

She stumbled, collapsed on the couch.  Her chest hurt. She sucked in breath after breath, but there was something wrong with the air here, it wasn’t right, it was sour and stifling and hot.  She gripped her shoulders, hugged herself, rocked back and forth on the cushion.

_What did you do, Mabel?  What in God’s name did you do?_

Her face burned with hot tears, her breath catching, and she buried her head in her hands, crying in shuddering, muted moans and hiccup-sniffles.  

How could she be so _stupid_ ?  Poking and prodding and pushing him.  Driving Dipper into a corner, demanding he reveal so many things she had no right to know.  And all this after … after she _molested_ him.  How _dare_ she?  How dare she make him relive it, make him talk about how it felt when his sister turned his own body against him?  What was she _thinking_?  

And then … taking off her shirt like that … flashing him like that … _of course_ he’d think she was just mocking him.  Heck, what if she … what if doing that actually got him aroused all over again?  God, that would just … that would just make him feel like a total pervert … ah, dammit, she was just having fun, just trying to show him she really didn’t mind …

He’s right.  It’s over. She and Dipper are over.  There’s no coming back from this. There could have been, maybe, if she hadn’t drawn him out of his shell just to hurt him all over again.  Oh God, why did she have to do that? Why couldn’t she just follow Dipper’s lead, give him what he so obviously wanted and needed and deserved, and let the whole thing drop?  Why did she have to put him in front of a spotlight, ask him where the Bad Sister touched him, make him show the wounds she had inflicted, and when he was helpless, why was she compelled to reach for those wounds, rip out the stitches, and make him bleed all over again?  Why? Why? _Why_?

She sobbed.  Burning brands of fire penetrated her chest, tore into her heart.   _Dipper_.  She loved him.  She loved him so much.  But it counted for nothing if she couldn’t love him the right way, the way he needed to be loved.  She thought she could show him there was nothing to be ashamed about, that they’d get through this together.

But she was wrong.  She was so, so wrong.  The parts of him he wanted to bury she kept digging up.  And now …

She wiped her face.

No. She wouldn’t give up.  Not on Dipper. Not ever. She’d figure this out.  Figure out what he needed from her. She didn’t have one of Dipper’s twenty-something-step plans, but she had _a_ plan, and she had all weekend to work it out.  Maybe she screwed it up, and maybe she just shook the tree and knocked out a bunch of talking points for them to deal with.  Maybe this was the right way to go about it. Maybe Dipper needed to be angry at her for a while to make this work.

Maybe this was the only way to get the truth out of him.  A truth that was clearly loathsome to Dipper.

A truth that made Mabel giddy and nauseous all at the same time, and perhaps, in equal measure.  That her brother was attracted to her. Sexually. And he _hated_ himself for it.

Yes.  Perhaps … perhaps that’s a truth the both of them might be best off spending some time to consider ...

 

* * *

 

They needed separate rooms, Dipper knew.  He needed one, tonight, most of all. Sharing a room with Mabel meant there was nowhere to retreat to after an argument like that.  

He was glad, at least, that Mabel stayed in the living room while he got ready for bed, and for a few hours more.  He had no interest in speaking with her, and the time she afforded him made it all the easier to curl up in the sheets, facing the wall, and feign sleep as she turned on the light.  

He braced himself for her to approach, or speak, but she never did.  He heard only the sliding of her dresser, clothes being shuffled around, and her retreat to the bathroom to get changed and brush her teeth.  When she returned, he could feel her step more heavily, and the snorts and snores of Waddles, followed by the creak of her bed as it took the weight of the pig and then Mabel herself.

She said “Good night, Dipper,” as she did every night, but this night of all nights he kept his silence, even though his chest ached.  The lights went off, and soon the snoring pig and creaks of the settling house were met with a soft breathing, muffled gasps, and the sound of Mabel blowing her nose.  

Dipper curled up tighter, squeezing his hands over his ears, drowning out the sound of Mabel quietly crying

 

* * *

 

Sleep did not come easily to Dipper, to the extent he wasn’t sure he slept at all.

His relationship with Mabel had clearly changed weeks ago, and it looked like it would stay that way.  No more wrestling. No more sharing blankets on the couch while watching a movie, or lying down in the same bed while reading.  All the casual physical contact that had been a major part of their lives was gone, because he just didn’t trust himself to permit it any longer.

But was that really so strange?  Wasn’t it perfectly normal for a brother and sister to grow out of that sort of thing?  No matter how much he missed that sort of physical contact, wasn’t it inevitable?

He lay awake long after midnight, watching the moon rise and fall again, not daring to turn his head and see if Mabel was across the room, staring him down, accusing him - and rightly so - of being the one responsible for closing this chapter of their lives.

He awoke to early-morning sunlight on his face, and continued clinging to sleep, his eyes closed and his arms reaching for a pillow to bury himself under.  Curling up against the warm fabric, his knees bumped into something solid at the edge of his bed.

“Mmf.  Go ‘way, Waddles,” he murmured.

No response, not even a grunt of refusal and the sound of the pig settling more firmly into the sheets.

“He’s still on my bed,” said Mabel.

Dipper jolted awake, scrambling backward.  Mabel sat at the edge of his bed, hands clasped before her.

“M-mabel!?”

She was so close.  Mere inches away. She was looking at the floor, her feet kicking off the edge of the bed, her eyes downcast.  He couldn’t help looking her up and down, and hating himself for it. Her red-brown hair cascading down her back.  Her purple headband. Her rosy cheeks, pink lips, button nose. The straps of her yellow tank top and pink bra on her shoulders.  The short gym shorts, white stars on baby blue. The bare feet she periodically stretched out, so that he could see the chipped green paint on her toenails.

“Mabel, what - what are you-?”

“Take it back.”

“Mabel?”

Her eyebrows furrowed, her expression souring.

“The promise you made.  That you’d stay away from me.  That you’d never touch me again.  Take it back, Dipper.”

“Mabel, I can’t … I can’t do that.”

“Why not?”

She turned to him, the tears in her eyes a dagger in his heart.

“Mabel, I already told you … I don’t … I don’t trust myself … it’s not safe to be close to you like that.  Not anymore. I’m sorry.”

She scooted herself further onto the bed, kneeling on the sheets beside him.  On reflex, he raised his hands in surrender, but she gripped them in her own.

“You’re wrong,” she said.

“I’m … _wrong_? Mabel, what are you getting at?”

She huffed in frustration, her hair gently spilling over her shoulders as she exhaled harshly.

“Dipper, you idiot,” she said.

She pressed his hands together and squeezed them between hers.

“Dipper, I _know_ you.  Like, I really and seriously _know_ you.  Better than you know yourself.  You’d never hurt me. Even if your hormones were raging like crazy, you’d never lose control.  So I’m not afraid of what might happen, Dipper. I’m not scared of you, not even a little bit. So you don’t have to be scared _for_ me.”

“Mabel, come on…”

“It’s not romantic, right?  Your feelings? The way you act around me - and the reason you avoid me - it’s not because you’re actually in love with me, is it?”

“N-no … no, it’s not … Mabel, I mean, obviously I love you.  You’re my sister and my best friend. I love you so much it hurts.  And that’s exactly why I can’t … I can’t let myself …”

He shook his head.

“Mabel, I’m not … I’m not _in_ love with you.  I mean, that would just be _insane_.  I just … I feel like my brain and my body are going two totally different directions ...”

“So it’s just … it’s just physical,” she said.  “You’re just … you’re just perving on me and that’s all.”

“Y-yeah.  Yeah, I think … I think that pretty much sums it up, Mabel.  I’m sorry. I’m so fucking sorry.”

She shook her head.

“God,” she said.  “God, I’m so glad.  If it was really serious … I wouldn’t know what to do.”

“Mabel?”

“Physical I can work with,” she said.  “Pervy stuff I can work with.”

She scooted closer, kneeling on the bed, her knees inches from where he sat, cross-legged, where layers of clothing and bedding concealing - or so he hoped - a rapidly developing erection.  It gave him some small comfort that this was more likely than not a fear reaction, but obviously it would make no difference to Mabel once she saw it. He withdrew, pulling his hands away from her grip, bunching the fabric on his lap and banging the back of his head on the wall.

Her eyes widened in surprise at his reaction, her gaze quickly flicking to his lap and back to his face, her expression softening into something he hoped was empathy but was much more likely to be pity.  

_Yes, Mabel.  That’s how it is right now.  I can barely even look at you without getting hard.  That’s how pathetic I am. My own sister turns me on like nothing else in this world._

“I’m sorry,” he whispered, tears welling in his eyes.

“No,” she said, shaking her head.  “There’s nothing … there’s nothing to be sorry for.  I know you can’t control it. I just … I don’t want it to control _you_.”

“Mabel?”

“I know it’s embarrassing, and of course it’s something you want to hide.  But if that’s the reason you don’t want to be around me … because your body keeps reacting when I’m close to you … I know it’s asking a lot, Dipper, but I hope you can put up with it, for my sake.”

“What do you mean, put up with it?”

“I mean … stay with me.  Don’t avoid me because you’re afraid … you’re afraid of getting h-hard...  And if you do … if that happens, and if it’s just the two of us … then don’t feel like you need to hide it.”

“Mabel, you don’t … you don’t want to see something like that …”

She reached for him, gripping his shoulders, and then tracing gentle fingers up and down his arms.

“It’s not that I _want to_ , I just don’t _care_ .  Don’t you see?  If we’re watching a movie together, and the only reason we’re on opposite sides of the couch instead of leaning on each other is because you’re afraid I’m going to see you get a dumb ol’ _boner_ … I mean, I guess I can live without wrestling you for a while, but if I can’t stretch out and lay across your legs anymore when we’re reading … if I can’t put my head in your lap when I’m tired … if that whole area is strictly off-limits now, and the only reason … the only reason is because your body is reacting to me like I’m a girl and not like I’m your sister …”

Her fingers rubbed uncertain circles on his shoulders.

“I know … I know I must sound crazy, but if that’s all it takes … if I just have to put up with that … it’s not even a contest, Dipper.”

Her fingers again moved down his arms, but this time, continued down his forearms, past his wrists.  Panic welled in him as she touched the back of his hands and gently brushed them aside, along with the wad of sheets with which he hoped to conceal his shame.  His boxers and loose gym shorts did absolutely nothing to restrict the extent of his erection, and Mabel blushed as she caught a full view of the tented fabric.

“Oh,” she whispered.

Sweat began to prick at the back of his neck.  He was incredibly, unbearably exposed. His erection was somehow large enough to make his arousal undeniable, yet still of completely inadequate size, to the best of his understanding.  

Here, then, was all Dipper’s sexual anxieties spread out at once - more boy than man, awash with urges and social awkwardness, developing a concept of masculinity, desiring it, measuring himself against it, and finding himself lacking in every conceivable way.  If only his voice would find a deep tone and stay there. If only his upper body would fill out. If only he could grow a beard, instead of this patchy mess on his chin and upper lip his family forced him to shave. But this … this part of him bothered him the most, for reasons he couldn’t explain even to himself.  It was just so unfair. Half of the male population had above-average-sized pensies. Why couldn’t _he_ be one of them?

She nodded slowly, and he had the crazy idea she was actually approving of what she saw.

“There,” she said.  “No big deal, right?  That’s just … that’s just a thing your body does.  I mean, it’s weird, for sure, but it doesn’t freak me out or anything.”

She was, nonetheless, blushing furiously.

“Does … does it hurt?” she asked.  

“N-no … I mean, it’s uncomfortable but …”

“I’m sorry,” she said.

“It’s not your fault.”

“I know.  But it’s not _your_ fault either.  So I’m sorry all the same.”

She shifted her hips.

“And I’m sorry because … Dipper, I really … I really want to lie down with you right now, and hold each other under the covers, like we used to.  But I think, in your condition, that’s maybe not a great idea …”

“That would be an _extremely_ bad idea, yes.”

“So I know I shouldn’t ask this … please don’t hate me for asking, but … can you … can you like … take care of things?”

“Take … care of things?”

She blushed, and raised a fist, making a brief pumping gesture.

“You know,” she said.

“Mabel, are you _serious_ right now?  Are you actually telling me to … you want me to …”

“I mean, not _here_ , dummy.  Or, yeah, if you want, and I’ll just wait outside until you’re done.  Don’t … don’t just whip it out or anything. There’s no way I need to see something gross like that.”

He recoiled at this, though he wasn’t sure why, as Mabel was completely correct.  There was no reason for Mabel to see something gross like that. He’d already disgusted her once with that sort of thing, and it was something of a relief to hear Mabel admit how unpleasant she found the whole event.

She turned away, her hands reaching for the sheets, gripping tightly as if to anchor herself.

“I’m sorry,” she said.  “That was mean.”

She shook her head.

“And it’s not true,” she said.  “It’s not … it’s not gross.”

“Mabel…”

“I mean it, Dipper.  What happened there … it was messy and weird, yeah, but I’m really, seriously, one hundred percent okay.  I don’t … I don’t want you to think there’s something wrong about your body, just because I reacted like I did.”

“Mabel, it’s all right.”

“ _No_ , it’s _not_ , Dipper.  I … God, I hoped I’d take this to my grave but … I _notice_ , you know.  When you take a little too long in the shower, or late at night, when you think I’m asleep, and I hear you breathing hard, and I know you’re … you know, _doing it_ .  I’ve always just ignored it.  I mean, I do the same thing, and I hoped if you ever knew you’d just ignore it too.  And you haven’t done _it_ since we were wrestling.  And maybe it has nothing to do with that, or with me, but … I really think it does.  I think I turned something that should feel really good into something you can’t enjoy anymore.”

“Mabel, seriously, you don’t … you don’t need to worry about stuff like that.”

“Is it because you’re thinking of me?” she asked.

“ _Mabel!_ ”

“I’m just _saying_ , if I’m getting in the way of whatever fantasy girl you masturbate to, it’s all right.  It doesn’t hurt me any. God knows I’ve had my share of times where the wrong person pops into my head.  In a situation like that there’s no choice but to keep going. If you just stop right there, that same person is going to keep reappearing again and again and you’ll never get the job done.”

“All … all right.  Not that I’m admitting to anything, but that … that’s a little reassuring, yes.”

“And it’s not gross,” she added.

“All right.”

“ _Seriously_ , Dipper, I _mean_ it.  I was upset when it happened, I know, but that was only because I thought I hurt you.  The way I looked at you then … I was _scared_ for you.  I thought that stuff was blood, for a second.  And when I realized what it really was … I mean, you weren’t even looking at me anymore after that, so you didn’t see … I was so _relieved_ , Dipper.  And, yeah, it was a real pain to clean all that stuff up, but I was so glad you were okay, physically anyway.”

“Clearly not mentally,” he said.

“No, I guess not.  Which is why I’m telling you what I’m about to tell you.  It was beautiful. You were beautiful.”

“Mabel, what the hell?”

“It was wrong, I know.  It’s something I shouldn’t have seen.  Some other girl should have seen you that way, and only when you were ready to show that to her.  I took that from you, and I’m sorry.”

“Mabel, come on…”

“I don’t want to give you the wrong impression.  I don't like you _that way_ , for the same reason _you_ don’t like _me_ that way.  But I also don’t want to go overboard and say it was horrible, it was gross, it was disgusting.  It wasn’t any of those things.”

“What … what was it, then?” he ventured.

A grin pricked at the corner of her mouth, and she looked away.

“It wasn’t for me to see,” she said.  “But I saw it. I didn’t really think about it too much when it happened - I was too confused, too freaked out - but now that I have time to think about it  … I don’t know. I don’t think ‘like’ is the right word. But I realize now it was something really special. It’s like a secret I accidentally overheard. I shouldn’t have it, but I do.  I know what you look like when you cum. The faces you make, the sounds, the way your body moves. If we still had that memory-eraser gun I’d use it in an instant - not because I can’t deal with the memory, but because it wasn’t mine to have in the first place.  And if I can’t do that, I’m going to _keep_ that memory, I want to remember it honestly.  I don’t want to call it gross or weird just because I’m supposed to.  Because, looking back now, I think it was pretty amazing. Someday some girl is going to see exactly what I saw and it’s just going to rock her gosh-darn world.”

He turned away.

“You … you don’t mean that Mabel.”

“I do.  I totally mean it.  And I’m sorry it’s taken me so long to be honest with you.  You laid it all out for me last night, just bared your soul to me.  I thought I did too, but I realized afterward that I’m still holding back.  You see … when that happened … I was really close to getting off myself. I didn’t even realize it until after.  And if things were just a little bit different … I think I would’ve popped too. You would’ve seen me in exactly the same way I saw you.”

“S-seriously?”

She nodded.

“And I think that would’ve been way better,” she said. “If you saw me like that, maybe you’d understand the way I feel.  And I wouldn’t feel like I stole something from you that I can’t give back. We’d … we’d just be _even_ , if that happened.”

She scooted backwards on his bed, pushing the comforter back as she knelt on the sheets.

“Mabel?”

“I know … I know it’s not the same.  I got to prepare for this moment. I’ve been thinking about it since last night, weighing all the pros and cons until I finally decided to just go ahead and do it.  You never got that chance; it just happened without you even wanting it, because of me. But maybe that works out, even if it’s not completely fair to you. I’ve been telling you over and over that I’m okay, and I love you just as much as I always have, and there’s nothing for you to feel embarrassed about, and it’s just not sinking in.  So I’m gonna try something else. Maybe it’s a little drastic, and maybe it’s a bad idea, but I want to try it. You see … you showed me something really special that nobody else has ever seen, although you didn’t mean to. And I want to do the same thing for you. Because I want to. Because I think you deserve to see it. And also … I trust you, Dipper, so I know you won’t take advantage, or use this against me.”

She scooted backward, his bunched up comforter at her lower back, and crossed her legs, so she was now sitting indian-style at the foot of his bed, while Dipper did the same at the head of his bed, his pillow just behind him.  There was no small sense of relief in Mabel moving further away; he could feel the temperature in the room rising, his skin flushed, and he needed every inch of the three feet of space between them to maintain any semblance of control.

Mabel’s words rattled around in his head, a handful of shapes that refused to fit into any slots in his brain.  He was starting to believe her now, that she wasn’t as upset as he thought she was, and that maybe, just maybe, he’d be able to get his head on right and enjoy physical contact with Mabel again.  But he didn’t comprehend - his mind wouldn’t let him comprehend - what it was that Mabel was going on about now.

Mabel’s hand moved from her knee to her inner thigh, tugging gently at the bottom of her star-patterned cotton gym shorts.

“Stay with me,” she said.  “Please. I know it’s weird.  I know it’s not what you want.  But I think this will fix everything, Dipper.  I really do.”

Her knees and pelvis made a wide triangle, her right hand moving to its apex.  She touched herself over her clothes, her palm splayed over the juncture of her thighs.  At first, it was almost innocent, a flat hand hovering over that part of her, her hand just another layer of obstruction along with her shorts and (he assumed) panties, shielding his view of her sex.  That changed - _everything changed_ \- when she curled her fingers into the space between her legs, her pointer and pinky fingers splayed out on her inner thighs, her ring and middle fingers matching the curvature of the body beneath Mabel’s clothes.

 _Fuck._  He turned his head away but immediately turned back.  Drew a hand to cover his eyes but let it down again. Tensed his legs, ready to spring off to his left, hit the floor on all fours, and scramble out the door of the bedroom.  But he couldn’t. He was transfixed. Astounded. And he was hard before but _this_ … this was something different.  It wasn’t just physical arousal anymore.  There was another powerful level there. This was … this was _desire_ .  Unabashed, unapologetic, unstoppable desire.  He could feel the heat on his face. Whatever Mabel was doing … whatever she was _going to do_ … he couldn’t tear himself away.

“Wow,” she said softly.”

“W-what?”

“Sorry,” she said.  “I just … the way you looked at me just then … I haven’t even _done_ anything yet and you’re already so …”

“Mabel …”

“Just … just gimme a minute, okay?  I’m a little nervous.”

“Take … take your time,” he said.

She touched herself, in slow, wide circles, spirals and figure-eights, sometimes with her entire hand, but mostly with her index and middle fingers, and after a minute or two those fingers zeroed in on a small spot and began to move faster, in tiny circles, and side-to-side motions, and Dipper realized he was watching Mabel play with her clitoris.

 

* * *

 

Mabel closed her eyes, trying to focus.  It was such a weird feeling. She’d done this plenty of times before, masturbating in the bedroom with Dipper, but secretly, in her own bed, hoping that Dipper was asleep.  Which is to say, she was often thinking of Dipper while she did it, but those thoughts were more along the lines of “Is he still asleep?” and “Don’t wake up.” But that still meant he was in her head, even then.  Listening to his slow, steady breathing. Looking at him sometimes, to make sure his chest was rising and falling, to study his face, ready to stop immediately if he gave any indication he was awake, or could hear her.

She hadn’t realized before that Dipper’s presence made things a little easier.  Obviously, she wasn’t turned on by him or anything like that. But she couldn’t really get started unless she felt she was in a safe place, and her bed felt like a very safe place indeed with Dipper on the other side of the room, even if he was asleep.  It’s not like she expected some awful creature from Gravity Falls to kick down their door or anything. But _if_ that happened, she _knew_ Dipper would be on his feet instantly, standing between her and the danger, as he always did.  And though she could never, ever tell him so, sometimes, late at night, she’d fantasize about this, about Dipper standing before her bed, arms outstretched, shielding her from whatever occult horror followed them on the bus from Oregon, his voice cracking just a little as he shouted in implacable defiance, “Stay away from my sister!”  And the creature would recoil from this, and flee, realizing all at once that it had chosen poorly, and could never hurt her so long as Dipper was there. The fantasy ended there, just dissolved away, although sometimes Dipper closed the door with a parting shot of “And _stay_ out!” and returned to his bed, glancing quickly at Mabel to see if she was okay, but not realizing she was just pretending to sleep, and certainly not realizing her hand was between her legs.

But this was very different.  Dipper was looking at her but trying not to, or maybe, trying to look at her but failing - she wasn’t really sure.  She half-expected him to just get up and leave, despite her requests. She was ready for that, humiliating though it might be, because that too would balance things out, and leave Mabel with the same sort of embarrassing experience that _she_ had accidentally given _him_.  But she really, really wanted him to stay.

She opened her eyes again, finding it easier now to study his face as she warmed herself up.  And she convinced herself that this wasn’t quite as wrong as it might have sounded. It’s not like Dipper could _see_ anything, and she was only touching herself over her clothes.  If he was really paying attention - and Mabel wasn’t sure he was, since his gaze seemed to cycle through the ceiling, the spot of bed between them, her face, and the two fingers rubbing herself firmly through her shorts - then Dipper might realize what she was doing, and that she was touching a very specific spot.  But that was only fair. He’d been on display for a while now, his erection straining against his shorts, and Dipper was continuing to honor her requests to not hide it. And she’d told him she didn’t care, but that wasn’t entirely true, because she’d been paying attention to it for a while, with growing curiosity. Not that she would ever ask him to show it to her, but she couldn’t help putting the pieces together in her mind.  The fabric strained over it so tightly she could make a good guess on the basic dimensions, and for a second or two, after their wrestling match, she saw the tip of it sticking out of his shorts after he came on her leg.

And during that wrestling match, even though she too was aroused, Dipper clearly had no idea. She had nothing to strain against her clothes to betray her arousal, or reveal the shape or size of her sex.

So it seemed only fair for Dipper to, likewise, learn a little about her own anatomy.  He probably understood now the significance of the spot she was rubbing so intensely, and perhaps he too was putting the pieces together.  She had the urge to tell him, to dictate what she was doing, and how it felt, but she’d die of embarrassment before getting the first word out.  

She remembered, too, seeing Dipper’s browser history when borrowing his laptop, and finding herself unable to avoid looking at his … shall we say … “preferences.”  And she laughed about it at the time, skimming through a few porn videos and searches for lady bits, although she made sure to never say anything to Dipper or anyone else.  But not long after, she realized his interests were refreshingly wholesome. The porn videos - which she _did_ skim through - were mostly body-positive “for women” stuff, and the Google searches of “how to pleasure a woman” and “what does a clitoris look like” were pretty good indicators that Dipper, though lacking in any sexual experience, had at least done his background research.

Which is all to say that she didn’t need to tell Dipper she was playing with her clit right now; she was pretty sure he knew.  What he probably _didn’t_ know was just how hard it was getting beneath her fingers, and that her labia were just starting to tickle with a growing wetness.  And she suspected he didn’t know what she was going to do next. Heck, _she_ didn’t know either.  She could cum this way if she wanted to, if she had to, just rubbing herself over her clothes.  That was more or less the plan, really - she figured an audience would make it impossible to get wet.  But as she rubbed herself she felt that satisfying warmth spread all over, rubbing herself in wider circles now, not only playing with her clit but the area around it, caressing the heated flesh until she began to feel warm and slick, to the point she worried if she was making a wet spot in her shorts.

She realized Dipper wasn’t looking away anymore.  He was blushing, yes, but his eyes remained on her, not darting back and forth, but moving up and down her body with a deliberation and confidence that made her heart flutter.  And as for the situation in Dipper’s shorts … well, he was hard before, but not like _this_ .  She was pretty sure he’d transitioned from “morning wood” straight through “awkward boner” and was now sitting pretty at “proud erection.”  Or at least, she hoped. It had upset her to see his frustration earlier, to be physically aroused but emotionally unready, even disgusted by his body’s reaction.  But now, she suspected, things were in sync. His look, his posture, his quiet and respectful observation, all convinced her he was enjoying himself, even if that was hard to believe.  And while she wasn’t sure she was ready for him to look at her that way, it made her happy all the same. He was hard, and he _wanted_ to be hard.  She wanted to tell him how glad she was for that.  As weird as it was to be the catalyst for such a thing, she regret nothing.  Seeing Dipper comfortable in his own skin was worth all this and more.

He covered himself for a moment with his hands, or so she thought, but when he drew his hands away again she realized he was just adjusting his clothing.  The tent peak at the center of his groin disappeared, but now the left leg of his cotton shorts conformed to an unusual shape just beside his thigh, making her breath catch.  He wasn’t exposing himself, although to be honest, she wouldn’t mind that very much at all. But he’d _moved things around_.  As in, he touched himself, if only for a moment, while she was watching.  

She’d done her own “background research” and had a general idea of what Dipper might look like under there.  He probably had fuzzy dark-brown hair in the triangle over her pelvis, just like she did. She had no idea what his balls might look like, but she assumed they were nice, or at least, not specifically unattractive.  And his penis was most definitely poking out of his boxers now, either through the leg or a flap in the middle, his cotton shorts delicately draped over the head a few inches down his left thigh.

Clearly, this was done to ease his discomfort, but she realized also he was removing any obstructions to his physical arousal.  She’d seen his awkward boners before, but through his clothes, with fabric restraining him from his full potential. For the first time, in her presence, Dipper was letting himself become as hard as he can.  Heat swelled in her chest as she watched the shape in his shorts throb as it continued to grow without restraint.

“Mabel,” he said, but stopped at her sudden moan and quick movement.  Her name on his lips, for reasons she couldn’t determine, made her thighs quake, and she brought her hand up to her waist and plunged it under the waistband of her panties, an almost reflexive action as she felt liquid spill from deep inside.  In an instant, her fingers and palm were slippery wet against her vulva, the back of her hand sticky against her panties, but she at least saved herself the indignity of soaking her shorts.

As she made contact with bare flesh, instinct took over, and she began to stroke up and down her slit, moaning softly.

 

* * *

 

Dipper tried and failed to close his eyes, cover his face, turn away, or leave the room.  Everything about this was wrong, he knew, but as soon as Mabel brought her hand between her legs he knew he was a goner.

He was glad Mabel closed her eyes at first, as he felt less awkward staring that way.  Without the need to maintain eye contact, he could allow himself to rove eyes over Mabel’s body, and feel less like a loser when he focused on what she was doing with her hand.

What _was_ she doing with her hand?  She was touching herself, that’s for sure, stroking her vagina - no, vulva - or at least part of it.  He studied her movements, and managed to feel a bit more confident, his attention moving from her groin to her face and back again, finding no small amount of fascination with the expressions she was beginning to make.

She looked like she was scratching a particularly good itch, but moreso, her brows furrowing in concentration, her cheeks turning crimson.  And she focused on one spot and _oh god that’s her clit.  She’s playing with her clit.  Right now. Right here. She’s not just pretending.  She’s actually trying to cum. Holy Jesus._

Her eyes slitted open, and moved up and down his own body.  Her breathing was deepening, quickening, and she was looking at him the same way he was looking at her.  She licked her lips, and he knew it was probably just that her lips were dry, but doing that while staring at him, while furiously working her clit with one hand, moved his erection from “annoying” to “outright painful.”

There was no time to think about it; he just slipped both hands into his shorts, and felt the relief of his cock slipping through the fly of his boxers and down one leg of his shorts.  The head of his was searingly hot as it bounced against his thigh, and with the tourniquet of his cotton boxers out of the way, he could actually feel himself throbbing, swelling, growing.  He’s not sure he’s ever been this hard before, and he’s sure he’s never gotten to such a state without touching himself. A strange feeling came to him, the feeling that Mabel actually wanted him to get hard for her.  Why was that such a pleasant feeling to have?

She was staring at him more intently now, her ministrations becoming more erratic, and he realized she must have noticed his adjustment and probably didn’t care for it.  Did he think he was going to take advantage of her, and stroke himself? He wouldn’t blame her for thinking so. He should probably apologize, explain he just needed to fix his clothes, and promise to her he wouldn’t do something gross like jack off right in front her.

“Mabel,” he said, and his mouth froze with what she did next.

 _Holy shit holy shit holy shit_.

All right, so over-the-clothes masturbation was exciting enough, but _this_ … this was verging on sensory overload.  Mabel’s hand was in her shorts, rubbing herself, _rubbing her area_ , and as she moved her hand he saw a band of pink fabric rise above the waistband of her blue shorts and _oh Jesus those are her panties her hand is inside her panties she is making direct physical contact with her vee._

“Mmph,” said Mabel.

He could feel himself throb against his own thigh again, and without thinking, brought his hand to stroke himself through his shorts, but immediately drew his hand away, gripping the sheets beside him.

_Oh, God, I don’t think I can handle this._

 

* * *

 

She moaned softly, and to her surprise and delight, Dipper touched himself again, and it wasn’t an adjustment, it was a full-on stroke, a single but unmistakable grip-and-pump maneuver, and she couldn’t help but respond by bringing her fingers down to her entrance, swirling her middle and ring finger around the slippery flesh.  She didn’t mean to, but she thought of the way his shorts conformed around that part of Dipper as he grabbed it, demonstrating, if vaguely, the dimensions and hardness of his penis. Except she wasn’t calling it a penis anymore, at least, not in her mind. It was something else, something naughtier, more visceral. Something alive and responding to her in ways that excited her beyond measure.  Dare she think the word _cock_ ?  I mean, she could never _say_ a word like that, but she could _think_ it, and thinking it made the back of her neck get all warm and sweaty.  And, at the same time, she could certainly _think_ about doing things with it that she’d never ever actually do.

She pressed two fingers deep inside, as deep as they would go, feeling her own wetness surround them and spill from her, and imagined, for a split second, her fingers were something else entirely.

 

* * *

 

The sounds were going to kill him.  Mabel’s soft moans, caught breaths, sudden inhales and exhales, were already doing him in, but he could hear _that part of her now_ now.  Down below.  Wet and squishy sounds, muffled by her clothes.  And since he didn’t think she’d go so far as to secretly palm a travel-size container of … whatever it is a girl might use for that … he had to assume that wetness came from her own body.  And that sent Dipper reeling all over again. He’d always assumed that was just a thing that happened in porn.

“Dipper,” she whispered.  “ _Please_.”

 _Anything_ , he thought.  She could ask him for anything in the world.

“You gotta,” she continued.

She was breathing hard, barely finding spaces between breaths for words, her right hand moving quickly between her legs, her left hand gripping her knee as she leaned forward toward him, her shoulders shaking.

“You gotta … do yourself ... please...”

Her eyes glistened, lips parted, ragged breath through her teeth.

“Mabel, are you sure - you really want me to?”

She nodded vigorously.

“ _Please_ , Dipper.  I don’t think … I don’t think I can keep going if you don’t …”

“All … all right, if you … if you really need me to …”

They locked eyes as he reached for himself, fisting his cock through his shorts and beginning to stroke slowly.  

 

* * *

 

She moaned, and increased her tempo as Dipper began to touch himself.  He seemed to be teasing her, or perhaps he was just shy and needed time to work himself up.  Soon, though, his hand slipped down to his thigh, and up one leg of his shorts, and she imagined he was touching himself directly, fisting the end of his cock.

Her hips began to move on their own accord, but frustration was beginning to mount.  Her clothing was constraining her movements more than she anticipated. And at the same time, she noticed the sounds that Dipper was making, pleasing though they were, weren’t quite the same as what she’d overheard before.  And she realized it wasn’t enough. She was being greedy, she knew, but she really wanted to see him do it for real. Did he want the same thing from her?

 

* * *

 

His clothes were beginning to chafe on his erection; he felt pretty sure he couldn’t come this way.  Mabel’s attention remained fixed on his movements, but as he was doing the same to her, he somehow didn’t feel as self-conscious as he felt he should.

“Dipper, is that … how you do it?”

“Y-yeah, mostly.  Maybe not exactly.”

“What’s different?”

“I, uh … I usually take my underwear off when I do it.”

“Oh, yeah,” she said.  “Yeah, me too.”

“Is that … is that all right?”

“Yeah!” she said.  “Yeah, go ahead! I’ll take mine off too, if that’s okay.”

“S-sure,” he said.  

In tandem, the twins hooked thumbs into shorts and underwear, Dipper pausing a bit to guide his erection back through the flap of his boxers, and in an instant, shorts and boxers and panties lay in a heap beside Dipper’s bed, and both of them sat before each other, bottomless.

Mabel’s vulva glistened beautifully, flushed and pink beneath a triangle of curly red-brown hair, and his cock throbbed with pleasure.

 

* * *

 

Dipper’s penis stood beautifully, flushed and red and rising beneath curly red-brown hair, and something inside her tightened another notch upon Dipper’s presentation of his anatomy, and once more as he took it in one hand and began to stroke it for her.

_God._

She began touching herself again, lifting herself up on her knees as the muscles of her thighs tensed.  A particularly good tingle worked up her spine, making her shiver, and suddenly she found herself pitched forward.  But before she could reach out, Dipper was there, gripping her shoulders, holding her still and safe.

“S-sorry,” they said in unison.  Neither of them had any intention of getting this close, but now that they were, she found it difficult to back away.  And if Dipper worried that he’d done something wrong by bringing his face to within inches of hers while they were in such a state, her decision to continue masturbating ought to have dispelled him of that notion.

And speaking of which, with Dipper so close to her that she was straddling his knee, with both of his hands on her shoulders to keep her from toppling over.  Which meant that the pleasantly warm object rubbing gently but insistently against her inner thigh was …

Something began to build and tense up beneath her, a swelling need, water threatening to overtop a damn, and she shivered.  It felt different than usual. More intense, with tingling sensations in new places.

“Dipper, I think I’m gonna…”

“Mabel, it’s okay,” he says.  

She screwed up, she knew.  Dipper was really enjoying himself, and maybe would have cum if she hadn’t interrupted him.  She should tell him she’s okay, that he should continue, but she’s not okay, because she needs him to hold her, not only to keep her from toppling over, but to grant her the reassurance she realized she can’t finish without.  Dipper’s hands are firm on her shoulders, keeping her steady, fingers massaging the flesh. She thinks he’s saying something to her, that it’s okay, that she looks beautiful, that there’s no hurry, and she can cum whenever she’s ready, because he’ll hold her as long as she needs it, but the ringing in her ears was drowning out most of the words.

With one last, desperate moan, she slipped fingers out of herself and rubbed her clit at a rapid pace, her free hand, damp and slick with herself, wrapped around Dipper’s back as she pressed her forehead to her shoulders.  

She knew she was wet, and if she wasn’t careful, she might drip on him.  But she didn’t realize how intense this orgasm was going to be. Not until she felt the pleasant yet alarming sensation of warm liquid beginning to build up somewhere inside her.

 

* * *

 

He’s not touching himself anymore, as both her hands were supporting Mabel, holding her close, but he thinks the sounds and scent of her might be enough to make him cum anyway.  The soft, keening moans, caught breath and hissed whispers, stood in beautiful contrast to the obscene orchestra taking place between Mabel’s legs. Squishy, liquid sounds, the slurp of flesh as she moved fingers in and out.  

She trembled in his arms, and he pulled her closer, her shoulder jabbing her stomach as - he suspected - she approached her climax.

“Sh-shoot,” she hissed. “I’m gonna … I think I’m gonna … m-make a mess…”

“Ssh, it’s all right.”

“S-seriously … m-maybe you should get a towel ….”

“No way, Mabel.  I’m not moving.”

“Your sheets…”

“I’ll wash them.”

“It’s gonna get on you…”

“I don’t care.  Don’t stop, Mabel.  Don’t you dare stop.”

 

* * *

 

She froze, tensed up, tried to step back from the cliff she had already begun to fall from.  She was never wet like this before. Never had that intense feeling of something ready to spill.  Or _had_ she, and she just never realized what it was until now?  The feel of something tightening, swelling, building. There was a particular feeling when she touched herself, and when she came, seemed to swell for a moment and then fade into the background as she came.  This time was different. It wasn’t going to fade. It was going to explode.

Her hips bucked as she rubbed her clit.  In her gyrations, she made contact with Dipper’s leg, and in that contact, realized how slick and slippery she was, her sex sliding along a few inches of Dipper’s thigh.  He groaned in her ear, not a sound of disgust, but of pleasure, like he enjoyed being sticky with her.

In that moment, all control was lost.  With a low, guttural moan, she came for him, the sensation of cumming heightened by the feel of liquid spilling from between her labia.  She was overflowing with something strange. Tears streamed from her tightly-clenched eyelids, the pleasure of orgasm and relief of letting go of … whatever it was she was letting go of … crashing headlong into the embarrassment of being so close to Dipper and feeling something come out of her.  

 

“Keep going,” he said.  “I’ve got you. No matter what happens, I’ve got you.”

Stupid Dipper!  She could have held back if he didn’t say stuff like that.  But now it was much too late. She continued to touch herself, driving herself beyond the point where she’d normally stop and let herself be carried off by the waves of pleasure, reaching a peak she’d never really brought herself to before.

“Dipper,” she gasped.  “Please. I gotta …”

“It’s okay, Mabel.  Go ahead. I want to see it.”

She realized, just then, she wanted him to see it too.  Whatever _it_ was.  And she collapsed against him, because it was too much, and her clit became too sensitive to rub anymore.  She pressed her hand to her vulva and felt her juices spill between her fingers, and succumbed to the temptation to spread her labia as she surrendered to the spasms that threatened to break her.

All the while, Dipper held her close, whispering soft assurances to her, how beautiful she was, how happy he was, even as she came on him in a sudden gush.  Her orgasm continued on.

She gyrated and quivered on his lap, her sex dangerously close to Dipper’s own, and soon she was resting her chin on his shoulder, sucking in breaths, the receding waves of pleasure magnified by the scent of his hair, the feel of his body, the fingers caressing her back, Dipper’s touch and presence a new and thoroughly welcome aspect to her afterglow.

“I’m sorry,” she whispered, though that was not entirely true, because she’d do it all over again if she could.

“Nothing to be sorry for.”

“I made a mess,” she said.  Which was entirely true, but she said it as if she regretted what she’d done, which … well, she did, somewhat, but not to the extent she should have.

“I liked it,” said Dipper.

Another quiver of pleasure shot through her at those words -  almost an aftershock, really. She managed to wipe the tears from her eyes, and shake the blur from her vision, and saw Dipper before her, smiling, eyes sparkling, looking happier than she’d seen him for a long time.

She inched backwards, still straddling his thigh, but looking over what she’d done, and her cheeks burned.  The bottom of Dipper’s shirt was soaked, droplets of moisture dotted the patch of brownish hair above his penis, and - worst of all - his penis and testicles glistened with wetness.  She could see, also, the sheets beneath him were wet. And she could smell herself now, pungent and strange.

“Oh, God,” she whispered.

 

* * *

 

He’s overcome by her, by her movements, her expressions, and the otherworldly sounds she makes.  She’s having an orgasm, an honest-to-god orgasm, right in front of him, and he’s never seen anything so beautiful in all his life.

He feels warm liquid on his thigh, and for a moment he was afraid she’d actually peed on him, but the scent that hits his nostrils made clear this was something else entirely.  It was a strange, fragrant smell, better than any perfume, and it made him salivate. He was sure that this too was something that only happened in porn, but here it was, plain as day.  Mabel, his sister, was squirting for him. On him.

_Fuck._

He wants to hold her like this forever, but he can’t.  He aches for release. And there’s no shame this time. No worry, no doubt.  She came for him, and now he must come for her. He can’t not. Mabel was right.  This made everything better. It made everything right.

 

* * *

 

The fog is beginning to lift, and the realization that she’s honest-to-god _squirted_ all over Dipper begins to take hold.  This was bad. This was really, really bad.  

“Dipper, s-shoot, lemme get … lemme get a towel … ah, gosh, I’m really sorry … I’ve never …”

“It’s all right,” he says to her, and she’s disarmed by how he looks at her, a cool confidence that was so foreign to him.

“Dipper?”

“I don’t mind.  I like this stuff.”

“C-cmon, you don’t … you don’t have to say that … just to make me feel better.”

She follows his gaze downward, to his throbbing erection and thighs glistening with her essence, and runs his hand over his damp thigh.  He looks at her as he brings his hand over his mouth and extends his tongue, licking her juices off his palm. His eyes glaze over. He’s not faking.  He likes her taste. He likes her taste and he wants her to know. _Oh god._

He fists his cock, and strokes himself for a moment, and stops, running his fingers over his thigh again, smearing his hand with her cream as he takes himself in his hands again, and _oh god, he’s using that stuff he’s using me … he’s using my juices to get himself off … holy crap holy crap ..._

She gulped.  His apprehension had clearly melted away.  He looked at her right in the eyes as he stroked his cock, faster and faster.

“It … it feels good?” she asked.

“It feels amazing, Mabel.  Is this okay? Can I use what you gave me?”

_Oh my fracking crapcakes._

“S-sure,” she said.  “I m-mean, that’s … that’s what it’s for, r-right?”

He nodded, like they didn’t just acknowledge that Dipper was more or less virtually having sex with her, lubricating himself with the same fluids he’d feel if he was actually inside her and _oh sweet golly jebus._

She’d lost her mind, she knew.  There were rules to this engagement.  Mutual masturbation. That meant you can’t touch the other person’s stuff, and you can’t do romantic things either, but she kissed Dipper anyway, pressed her mouth to his, jammed her tongue inside, all that business, and - she suspected - really mucked up his rhythm, jackoff-wise.

“M-mabel?” he gasped, and she could cry for him, his sudden burst of confidence shattered so easily by her actions, so of course she had to respond and spur him on.

“Your turn now.  You gotta make a mess too,” she said.

She scooted close, straddled his thigh again.  His fist brushed against her pubic hair as he continued, but more slowly now, more unsure.

“Mabel …”

“You didn’t mean to do it last time,” she said.  “And I didn’t know it was gonna happen. But I know now, and I’m asking for it.  And I want you to do it on purpose this time. I got you all messy, Dipper, so you gotta get me all messy too, or I’m gonna feel all weird.”

She loves, loves, _loves_ the way he looks at her then, shock and pleasure and desire all wrapped into one.

“Mabel, you really want me to …”

“Yeah, go on and do it,” she said

His fist moves quicker, but his eyes turn away from hers.

“Mabel, I know … I know it’s stupid, but can you … can you tell me it’s okay?  Like … say it exactly?”

She grinned.  He wants her to talk dirty.  Holy crap, that’s amazing. And yeah, considering the circumstances, a hundred-percent doable.

She does the same thing that he did for her, getting close, arms over his shoulders.  His fist is bumping her thigh on the downstroke, but she doesn’t let it bother her.

“Sure, I mean … I don’t really know what to say, except … I don’t mind that stuff.  I mean, I already got it on be before, and it wasn’t so bad. So it’s okay. I know it’s totally weird.  But it’s really okay to cum on me, Dipper.”

“Mabel,” he groans, and she knows she’s on the right track, that he’s really close.  “I want to. I just … You gotta … you gotta be careful with this stuff…”

He’s right, of course.  She checks the angles, makes sure it’s safe, that he won’t do anything that might make her pregnant.  The head of his cock is pointed at her right hip, so everything should work out great. She can make as much of a mess as she likes, but Dipper’s stuff … that stuff _does things_ .   _Biologically_.  So she needs to be careful.  But she’s being careful, so it’s all right.  Everything’s all right.

“Don’t worry.  I know where it’s gonna go.  Just keep going,” she says. “It’s safe.  Trust me.”

“Ah, f-fuck…”

She kissed him again, even though she knew she was messing up his rhythm, and held his face before hers.  She wanted to look at him, and enjoy every little aspect of his expression as he came for her.

 

* * *

 

He was close, so very close.  The taste of Mabel lingered on his tongue, the taste of her mouth mostly, but also … dare he call it … Mabel’s _pussy_.  A sweet, salty, tangy taste, filling him with desire, the fragrance lingering about them, the feel of it slippery between his fingers.  He loved it. Loved the taste, the scent. Loved the way her juices felt on his cock.

“Mabel, I … I love you,” he gasped, the words slipping through his teeth before he could catch them, the shock of his admission making both of them tense up at the same time.”

“Dipper,” she whispered.  “I love you too. I love you so much.  And that’s why it’s okay. You don’t have to be embarrassed.  You can show me everything, Dipper.”

He groaned, and finally, found release.

The relief was immeasurable, indescribable.  He grit his teeth as he came, and Mabel’s face went blurry, but her eyes remained fixed on him, jaw set in resolution.  He found comfort in that.

And when he was spent, she held him still, even though she was befouled by him, sticky with him, even though his cum lay in streaks and globs on Mabel’s thigh, and belly, and pubic hair.

His afterglow was brief, fear of wrongdoing rapidly dissolving the mist of his orgasm.

“Mabel, I’m so sorry,” he whispered.

She pursed her lips, and touched her thigh, the place he’d soiled her, index and middle finger capturing a sample of his semen, and she held this before her face a moment, sniffed, and plunged fingers into her mouth.

He groaned.

Her face tightened up a moment, then tensed, and a grin formed on her face.

“Mabel?”

“So weird,” she said.  “Kinda bitter. But also kinda yummy.”

_Fuck._

She grinned, and brought her hand back to her thigh, smearing his cum all over her belly.

“Now we’re even, right?” she said.  “You’re all wet with me, and I’m all gooey with you.  And we’ve tasted each other’s stuff, too. So we don’t have to hide that kind of stuff from each other anymore, unless we want to.”

“R-right,” he said.  “Yeah…”

She laughed.

“Gosh, though,” she said.  “This is like, level five cleanup here.  Showers for all. Full load of laundry. And we’ve got like three hours before Mom and Dad come home.  So we’re gonna need to do some teamwork here.”

“Yeah, yeah, of course.  You clean up first, Mabel.  I’ll grab the sheets, and the clothes, and …”

He trailed off as Mabel stood and divested herself of the last of her clothes, her shirt and bra falling to the floor, her beautiful breasts on full display, small and pert with pink nipples.

“Don’t put that bra through the dryer,” she said.  “It melts the plastic parts.”

“Gotcha.”

She kissed him one last time, an exaggerated “Muah!” on the lips, and Mabel, his sister, the girl he loved more than anyone else in the world, skipped to the bathroom.

The scent of her lingered as he dragged his bedsheets and their clothes downstairs, and ran them through the washer.  They traded the bathroom twenty minutes later, and the hot water heater ran out shortly after, and he rinsed himself with cold water.

The next few hours were spent arranging a farce.  Replacing his sheets, as if never washed. Cleaning up the bedroom and spritzing it with Febreeze to mute the smell of raw sex.  Arranging themselves in the living room, playing on their phones, Mabel’s legs splayed over his lap again, as they ought to be.

**END**

 

 _Will you live to eighty-three?_  
_Will you ever welcome me?_  
_Will you show me something_  
_That nobody else has seen?_  
_\- R.E.M._

 

 


End file.
